Value of the Electrocardiogram in Determining Cardiac Events and Mortality in Myotonic Dystrophy

Myotonic dystrophy is the most common muscular dystrophy affecting adults[ 1 Harper PS. Myotonic Dystrophy. 2nd ed. London: WB Saunders, 1989. Google Scholar ]and is caused by an expansion of a cytosine-thymine-guanine trinucleotide repeat on chromosome 19.[ 2 Harley HG Brook JO Housman DE Expansion of an unstable DNA region and phenotypic variation in myotonic dystrophy. Nature. 1992; 255: 545-546 Crossref Scopus (696) Google Scholar , 3 Buston J Shelbourne P Davies J Jones L VanTongeren T Aslanidis C de Jong P Jansen G Anvret H Riley B Williamson R Johnson K Detection of an unstable fragment of DNA specific to individuals with myotonic dystrophy. Nature. 1992; 355: 547-548 Crossref PubMed Scopus (594) Google Scholar ]Conduction disturbances appear to be the predominant cardiac manifestation of this disease and early signs of conduction system abnormalities are evident on the electrocardiogram.[ 4 Perloff JK Stevenson WG Roberts NK Cabeen W Weiss J Cardiac involvement in myotonic muscular dystrophy (Steinert’s disease) a prospective study of 25 patients. Am J Cardiol. 1984; 54: 1074-1081 Abstract Full Text PDF PubMed Scopus (116) Google Scholar , 5 Olofsson BO Forsberg H Andersson S Bjerle P Henrikson A Wedin I Electrocardiographic findings in myotonic dystrophy. Br Heart J. 1988; 59: 47-52 Crossref PubMed Scopus (74) Google Scholar , 6 Hawley RJ Milner MR Gottdeiner JS Cohen A Myotonic heart disease a clinical follow up. Neurology. 1991; 41: 259-262 Crossref PubMed Google Scholar , 7 Fragola PV Luzi M Calo L Antonini G Borzi M Frongillo D Cannata D Cardiac involvement in myotonic dystrophy. Am J Cardiol. 1994; 74: 1070-1072 Abstract Full Text PDF PubMed Scopus (69) Google Scholar , 8 Prystowsky EN Pritchett ELC Roses AD Gallagher J The natural history of conduction system disease in myotonic muscular dystrophy as determined by serial electrophysiologic studies. Circulation. 1979; 60: 1360-1364 Crossref PubMed Scopus (95) Google Scholar ]Given the widespread access, the limited cost, and the relative ease of performing an electrocardiogram, we evaluated and followed patients with myotonic dystrophy to determine whether the electrocardiogram may be helpful in predicting long-term outcome and clinical events.